Systems for spreading and retracting coverings for architectural openings such as windows, archways and the like are commonplace. Systems for spreading and retracting such retractable coverings, may operate for example by raising and lowering the coverings, or by laterally opening and closing the coverings. Such window covering systems typically include a headrail, in which the working components for the covering are primarily confined. In some versions, the window covering system includes a bottom rail extending parallel to the headrail, and some form of shade material which might be fabric or shade or blind material, interconnecting the headrail and bottom rail. The shade or blind material is movable with the bottom rail between spread and retracted positions relative to the headrail. For example, as the bottom rail is lowered or raised relative to the headrail, the fabric or other material is spread away from the headrail or retracted toward the headrail so it can be accumulated either adjacent to or within the headrail. Such mechanisms can include various control devices, such as pull cords that hang from one or both ends of the headrail. The pull cord may hang linearly, or in the type of window covering systems addressed by the present invention, the pull cord may assume the form of a closed loop of flexible material such as a rope, cord, or beaded chain, herein referred to as a continuous cord loop.
In some instances, window covering systems have incorporated a motor that actuates the mechanism for spreading and retracting the blind or shade material, and controlling electronics. Most commonly, the motor and controlling electronics has been mounted within the headrail avoiding the need for pull cords such as a continuous cord loop. Using such motor-operated systems or devices, the shade or blind material can be spread or retracted by user actuation or by automated operation e.g., triggered by a switch or photocell.
However generally such motor-operated devices have been designed to replace the normal mechanisms that come installed with the window covering system. For homeowners who already have window blinds, installation of such motor-operated device requires the installer to remove the current blinds, retrofit it with the motors, then reinstall the blind. Such motor-operated devices are extremely burdensome or simply impractical for a typical homeowner to install, instead requiring installation by a trained service professional. This increases the cost of such devices.
Although it is known to design motor-operated devices for window covering systems for installation apart from the headrail, such system designs have been inadequate to permit installation by a typical homeowner. Installing such a motor-operated device requires mounting the device within or adjacent the architectural opening, and as architectural openings and existing window covering systems installations vary widely in configuration, the installation requires careful planning. Furthermore, such devices must work in coordination with the mechanisms at the headrail for spreading and retracting such retractable coverings, and remote mechanisms for operating such systems such as pull cords can easily fail due to misalignment, tangling, binding and the like. For these reasons, prior motor-operated device designs of this type also generally require installation by a trained service professional.
Another consideration in the operation of motor-operated devices for window covering systems is that it is desirable to permit manual operation of the window covering system, for example in the event that the motor-operated device loses power.
For the foregoing reasons, there is a need for motor-operated devices designed for operation with existing window covering systems over a variety of architectural opening settings. There is a need for motor-operated devices of this type that can be installed without requiring a trained service professional. Further, there is a need for motor-operated devices that permit manual operation of the window covering system, for example in the event that the motor-operated device loses power.